My friend and colleague Dan Slater is a close watcher of Indonesian politics with a distinctive view of powersharing and coalition politics in Indonesia (see here and here). His work is what I read when I want to be skeptical of ideology as a constraint in Indonesian party politics.

Does the current coalitional alignment signify a meaningful cleavage in Indonesian party politics (the type that I had suggested was possible over at the Monkey Cage several months ago, prior to the legislative elections)? Yes and no: the existence of the cleavage is consistent with at least three possible understandings of Indonesian party politics. We can think about the ideological differences across the coalitions as features, outcomes, or fundamentals of coalition politics.

Ideological differences across coalitions are features if they are ephemeral results of the dynamics of powersharing. This does not mean that they don’t exist: These differences can be described by analysts, and they may be invoked by politicians now that the coalition has formed (see Jokowi’s statement that he’s a representative of the moderate, inclusive Muslims), but they are simply incidental to the politics of coalition formation. The implication is that such ideological cleavages should not be sticky over time. After the current election, they will disappear.

Ideological differences are fundamentals if they are causes of the coalitional alignments. If, for example, the fact that PKS is an Islamist party prevents it from aligning with PDI-P because PDI-P is not Islamist, this would mean that ideological differences are fundamental to the coalitions that have formed. The prediction here is that ideological cleavages should endure over time. After elections end, they persist, and constrain what kinds of political agreements or coalitional alignments are possible. This does not rule out the possibility that coalitions could change in the future (for example, you can imagine both red-green and grand coalitions in the same country), but it does imply that these should be rare, and hard to sustain absent strong structural pressures.

Ideological differences across coalitions are outcomes if the observed ideological cleavage is the product of fundamental party characteristics other than ideology that constrain coalition formation. The distinction between fundamental and outcome is subtle but important. If, to take a counterfactual example, durable and institutionalized parties (think PDI-P, Golkar) were unwilling to align with personalist parties (think PD, Gerindra, Hanura), and the two groups of parties happened to differ in ideology too, then any ideological cleavages would be an outcome but not a fundamental. The observable implications of cleavages-as-outcomes are almost identical to those of cleavages-as-fundamentals: they should persist over time. The key difference is in the process of changing coalitional alignments, which requires ideological flexibility if cleavages are fundamentals but not if they are outcomes.